In general, wireless networks define a Quality of Service (QoS) concept to handle a quality of the service provided to a user equipment (UE). A “service” may be viewed as offering an operator of a network makes to a subscriber. Examples of services include voice over Internet Protocol (VoIP), real-time gaming, conversational video (live streaming), non-conversational video (buffered streaming), and so on. The traffic running in the wireless network can be divided into separate service data flows (SDF).
The traffic handling attributes for each SDF may be determined by a set of QoS parameters. Examples of QoS parameters are UE power settings, default uplink maximum bit rates, default downlink maximum bit rates, and so on. These can be dynamically signaled when the SDF is established.
In the 3rd Generation Partnership Project (3GPP), a specification is on going for the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), which is an example of a next generation of radio access network. Another name used for E-UTRAN is Long Term Evolution (LTE) Radio Access Network. A base station in this context is called E-UTRAN NodeB (eNB). FIG. 1 illustrates one such network architecture.
In 3GPP standardized networks as well as in other types of wireless networks, a service bearer is used to provide the actual service to the UE. A service bearer may be viewed as an edge-to-edge association between a UE and a gateway of the network providing the service to the UE. For example, in 3GPP, to provide E-UTRAN access to an evolved packet core (EPC), a packet data network (PDN) connectivity service is provided by an evolved packet system (EPS) bearer.
An association between a service bearer and QoS parameters define the characteristics of the service and the treatment with regard to, among others, policies for packet forwarding and scheduling. An example specifically related to LTE and 3GPP Release 8 is described as follows.
A service bearer (such as the EPS bearer), which is used by a network to provide the service to the UE, can be defined through a network to which the bearer connects the UE. In addition, the bearer can be defined through a QoS Class Identifier (QCI) via which it can be associated with a set of QoS parameters.
The SDF between the UE and the network can be bound by the set of QoS parameters associated with the service bearer. The service bearer is associated with an uplink traffic flow template (UL TFT) in the UE and with a downlink traffic flow template (DL TFT) in the network. 3GPP Release 8 (3GPP TS 36.300 V8.3.0, incorporated by reference in its entirety) defines an evolved Quality of Service (QoS) concept to allow a radio access network (RAN) to handle the quality of the provided services.
The QCI, in this context, is implemented as a scalar value used to reference access node-specific parameters that control the bearer level packet forwarding treatment including scheduling weights, admission thresholds, queue management thresholds, link layer protocol configuration. Note that the packet forwarding treatment can be configured by the operator owning the access node (e.g. eNB). The QCI can be viewed as a pointer.
Each SDF is associated with a single QCI. That is, each service bearer is associated with a particular QCI. Note that multiple service bearers can share the same PDN connection, i.e., can share a same IP-CAN session.
When setting up a session, that is, when setting up a service connection between the network and the UE, each SDF is mapped to a QCI. Each QCI, which represents a service or a service aggregate, is associated with one set of QCI characteristics. The QCI Characteristics are used to characterize the configurations of the access nodes such as the eNB. In 3GPP, nine different standardized QCI Characteristics are being defined. There will also be standardized one-to-one mappings between the standardized QCI characteristics in the 3GPP Release 8 and certain pre-Release 8 QoS attributes. A standardized one-to-one mapping between the 3GPP Release 8 QCIs and 3GPP pre-Rel8 QoS attributes is defined for handover or roaming between a network implementing the 3GPP Release 8 and another network implementing a pre-Release 8 QoS framework. With standardized QCI configurations, interoperability between operators is possible.
In addition to the standardized QCI characteristics of the 3GPP Release 8, an operator of a network is free to define QCI characteristics particular to the network in 3GPP. In other words, the operator has the freedom to implement proprietary QCI characteristics whose definitions are only known by and are really meaningful only to the network itself. Furthermore, the operator is not mandated to implement any of the standardized QCI characteristics relevant to the 3GPP Release 8. It is thus possible that operators of different networks will implement different sets of QCI characteristics. Between two networks, the least common denominator known by both parties is the common standardized QCI characteristics implemented by both operators.
When a service transition occurs, such as when a handover or roaming is performed, between two networks where at least one network implements the 3GPP Release 8, the main service identifier is the QCI. One way to allow interoperability between the different networks is the definition of the standardized QCI characteristics.
However, interoperability is not ensured for the service in the situation described. First, even assuming the QCI identifies one of the standardized characteristics, if the other network does not implement the 3GPP Release 8, interoperability will not occur. Second, again assuming that the QCI identifies one of the standardized characteristics, if the other network does not implement the standardized characteristics particular to the QCI (since the network is not mandated to implement all standardized characteristics), interoperability will not occur. Third, if the QCI is proprietary to the network, then interoperability will not occur.